package check

import (
	"encoding/json"
	"strings"
	"testing"

	"git.novox.be/novox/mesh-sdk/go/delivery"
)

// The failure the build module reported for group r4g on 2026-10-23: the test logged a line, then failed with a multi-line
// t.Fatalf. Its output is what the build module now sends (its last lines, with the error line as Cause).
func fatalAfterLog() Failure {
	return Failure{
		Package: "github.com/novox/mesh-controller/internal/broker", Test: "TestTheCataloguesDerivedSubjectsMeet",
		Cause: "3 subscription(s) derive to a subject no emitter owns:",
		Output: "    agreement_catalogue_test.go:130: judged against /var/lib/mesh-build-go-work/id/beside/mesh-catalog as cloned\n" +
			"    agreement_catalogue_test.go:186: 3 subscription(s) derive to a subject no emitter owns:\n" +
			"          a.b.c\n          d.e.f\n          g.h.i\n--- FAIL: TestTheCataloguesDerivedSubjectsMeet (0.00s)",
	}
}

func TestAFailedTestsVerdictKeepsItsWholeFailureMessage(t *testing.T) { // 1901/AC1
	v := levelFailure(&target{}, "unit", Tested{Failed: []Failure{fatalAfterLog()}})
	for _, want := range []string{"3 subscription(s) derive to a subject no emitter owns:", "a.b.c", "d.e.f", "g.h.i"} {
		if !strings.Contains(v.Failed.Words, want) {
			t.Errorf("words lack %q: %q", want, v.Failed.Words)
		}
	}
	if len(v.Failed.Words) > MaxWords+200 {
		t.Errorf("words are %d bytes, bound %d", len(v.Failed.Words), MaxWords)
	}
}

func TestTheStatusLineNamesTheFailureNotTheFirstLoggedLine(t *testing.T) { // 1901/AC2
	v := levelFailure(&target{}, "unit", Tested{Failed: []Failure{fatalAfterLog()}})
	got := firstFailed(*v)
	if !strings.Contains(got, "3 subscription(s) derive to a subject no emitter owns:") || strings.Contains(got, "judged against") || strings.Contains(got, "\n") {
		t.Errorf("firstFailed = %q", got)
	}
	// With no cause told apart (an older build module), the words still start at the first line, as before.
	f := fatalAfterLog()
	f.Cause = ""
	v = levelFailure(&target{}, "unit", Tested{Failed: []Failure{f}})
	if !strings.HasPrefix(afterHid(v.Failed.Words), "agreement_catalogue_test.go:130") {
		t.Errorf("words = %q", v.Failed.Words)
	}
}

func TestWordsLongerThanTheBoundKeepTheirLastLines(t *testing.T) { // 1901/AC1
	f := Failure{Output: strings.Repeat("log line of some length\n", 500) + "the cause is here"}
	v := levelFailure(&target{}, "unit", Tested{Failed: []Failure{f}})
	if !strings.HasSuffix(v.Failed.Words, "the cause is here") || len(v.Failed.Words) > MaxWords+200 {
		t.Errorf("%d bytes, ends %q", len(v.Failed.Words), v.Failed.Words[len(v.Failed.Words)-30:])
	}
	_ = delivery.VerdictFail
}

// An older build module sends no "cause": its answer is still accepted and the verdict's words are its output, as before
// (1901/AC3). A failure that hides its cause (none, or a passing line) is said loudly first in the words and in the status
// line, naming the build module and the version it says it is, and the level still fails; a failure that keeps the
// contract is worded as before (1901/AC8).
func TestAnOlderBuildModulesFailureIsAcceptedWithItsWholeOutput(t *testing.T) { // 1901/AC3, AC8
	old := `{"package":"p","test":"TestX","output":"x_test.go:1: logged\nx_test.go:2: the old kept lines"}`
	var f Failure
	if err := json.Unmarshal([]byte(old), &f); err != nil || f.Cause != "" {
		t.Fatalf("1901/AC3: err = %v, cause = %q", err, f.Cause)
	}
	v := levelFailure(&target{}, "unit", Tested{Failed: []Failure{f}})
	if afterHid(v.Failed.Words) != "x_test.go:1: logged\nx_test.go:2: the old kept lines" {
		t.Errorf("1901/AC3: words = %q", v.Failed.Words)
	}
	if got := firstFailed(*v); !strings.Contains(got, "the build module hid the failure") || strings.Contains(got, "\n") {
		t.Errorf("1901/AC3, AC8: status = %q", got)
	}

	by := "mesh-build-node with mesh-sdk v0.1.14-0.20261026184535-e40dd0f56a78"
	for _, c := range []struct {
		name, module, by, cause, output, loud string
	}{
		{"no cause", "mesh-build-node", by, "", "test/b.test.ts: something", "the build module hid the failure (mesh-build-node at mesh-sdk v0.1.14-0.20261026184535-e40dd0f56a78): it sent no cause"},
		{"a passing line as its cause", "mesh-build-node", by, "\u2714 the same merge has the same id (8.006913ms)", "", "the build module hid the failure (mesh-build-node at mesh-sdk v0.1.14-0.20261026184535-e40dd0f56a78): its cause is a passing line"},
		{"from before the contract", "mesh-build-node", "", "", "\u2714 the same merge has the same id (8.006913ms)", "the build module hid the failure (mesh-build-node at a version before the failure contract): it sent no cause"},
		{"a real cause", "mesh-build-node", by, "one plus one is not three", "not ok 3 - fails", ""},
	} {
		t.Run(c.name, func(t *testing.T) {
			v := levelFailure(&target{module: c.module}, "unit", Tested{By: c.by, Failed: []Failure{{Package: "modules/gitea", Test: "fails", Cause: c.cause, Output: c.output}}})
			if v.State != delivery.VerdictFail {
				t.Errorf("1901/AC8: the verdict is %q, want it failed", v.State)
			}
			line := firstFailed(*v)
			switch {
			case c.loud == "" && strings.Contains(v.Failed.Words, "hid the failure"):
				t.Errorf("1901/AC8: a failure that keeps the contract is said hidden: %q", v.Failed.Words)
			case c.loud != "" && (!strings.HasPrefix(v.Failed.Words, c.loud) || !strings.Contains(line, c.loud) || !strings.Contains(v.Failures[0].Words, "hid the failure")):
				t.Errorf("1901/AC8: words %q, status %q, want both to start with %q", v.Failed.Words, line, c.loud)
			}
		})
	}
}